Plasticizers have the ability to reduce the glass transition temperature of polymers and thereby provide soft and/or flexible products. Plasticizers are often based on esters of polycarboxylic acids with linear or branched aliphatic alcohols of moderate chain length. Organic ester phthalates are widely used plasticizers. The most commonly used phthalate esters are di-2-ethylhexyl phthalate (DEHP), also known as dioctyl phthalate (DOP), diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP). These aromatic dicarboxylic plasticizers are commonly synthesized from terephthalic acid or dimethyl terephthalate and the corresponding alcohol. There is a growing interest in the use of renewable resources as feed stocks for the chemical industries mainly due to the progressive reduction of fossil reserves and their related environmental impacts.
Furan-2,5-dicarboxylic acid (FDCA) is a versatile intermediate considered as a promising closest biobased alternative to terephthalic acid. Like aromatic diacids, FDCA undergoes esterification reaction with an alcohol such as 2-ethylhexanol to form bis(2-ethylhexyl) furan-2,5-dicarboxylate (BEHFD) plasticizer. BEHFD plasticizers can be synthesized from FDCA and 2-ethylhexan-1-ol (2-EH), in the presence of a catalyst as shown below in equation (1), or by transesterification of dimethyl furan-2,5-dicarboxylate (DMFD) with 2-EH in the presence of a catalyst as shown below in equation (2).
However, the above synthetic pathways to make BEHFD yield very highly colored plasticizer which makes its end use application less desirable.